This invention relates to ball bearing cages and particularly to an improved molded bearing cage for application in unitized angular contact thrust bearings.
Angular contact thrust bearings are designed to carry high, axially directed thrust loads. In some applications of such bearings it is desirable to utilize a bearing cage to retain the alignment of ball bearings between the curvilinear raceways of the bearing. Moreover, it is useful to create a unitized bearing assembly in which the races, ball bearings and bearing cage once assembled are held together as a unit prior to incorporation of the complete bearing into some other assembly.
One design of such a unitized angular contact thrust bearing heretofore proposed utilizes a bearing cage which also functions to hold the complete bearing together as a unitized assembly. The bearing employs inner and outer bearing races designed to provide confronting curvilinear raceways, ball bearings and a bearing cage made of a resilient injection molded material. The bearing cage in this bearing extends through the raceway region, has ball bearing cavities functionally designed to retain the balls in their proper alignment and has retaining lips to engage respectively the upper and lower surfaces of the inner and outer races and which retain the races together as a unitized assembly. However, the bearing cage design heretofore proposed is unsuitable for efficient injection molding production. The retaining lip of the previously proposed bearing cage design employs certain undercuts which make the bearing cage practically impossible to manufacture by injection molding processes alone without some amount of machining to produce the undercuts. Inasmuch as there is a significant economic advantage to manufacturing the completed cage by injection molding processes alone as compared to molding and then machining, it has been highly desirable to devise a cage design which can be produced in completed form by modern injection molding processes.